Lawn tractor maintenance overview: Save $150 in one morning!

Lawnmower maintenance kit

The kit includes everything you need for basic maintenance. A tube for a tubeless tire repair is extra.

Following the lawn tractor maintenance advice in your tractor’s manual
is the best way to keep it humming along smoothly.
But owner’s manuals usually only tell you basically what
to do and when to do it—they seldom include the tips and real-world
wisdom gained through experience. So we asked veteran
mechanics which steps are the most important and how to
make lawn tractor maintenance and tubeless tire repair faster and easier.

You’ll save too. Dealers typically charge more than $200 for routine
maintenance that includes an oil change and
new spark plugs and filters. But you can
do all these things—and more—in
just a few hours. A lawn tractor maintenance kit
from your dealer (less than $75)
might cost a few bucks more than
buying parts separately but
ensures that you get all
the right stuff. And new tubes for a tubeless tire repair cost from $5 - $15.

Blow the mower deck clean

Clean the mower deck

Remove the belt guards and blow off
the debris that wrecks belts and pulleys.
Scrape away any debris buildup
under the pulleys with a screwdriver.

Close-up of belt guard

Belt guards trap grass and debris that wears on the belts and pulleys.

You might think that the belt guards on top of
a mower deck protect the belts and pulleys
from grass clippings, dirt and other debris.
But just the opposite is true. The spinning
belts and pulleys suck in debris and the
guards trap it inside. Then it swirls around,
grinding away at the pulley surfaces and tearing
up your belts. Once a pulley wears, it will
quickly chew up every new belt you put on.
Avoiding expensive belt and pulley replacements
is easy; just blow the deck off with an
air compressor or leaf blower after every third
or fourth mowing.

Spark plug pointers

Change spark plugs

Spark plugs are the most important but least expensive components
in the engine. Change them regularly for easy starting and
fuel economy.

Worn spark plugs cause a variety of problems, from hard
starting and poor fuel economy to misfires and even engine
damage. So replace them at the manufacturer's recommended
intervals. Changing plugs is a simple matter of unscrewing the
old ones and screwing in new ones. But there are a few things
to keep in mind:

Prevent debris from falling into the cylinder by brushing or
blowing around the plug before you remove it. After
removing the plug, wipe out the spark plug seat with a clean
rag.

If an old plug won't turn, don't resort to a bigger wrench.
Brute force can cause major engine damage. Instead, use a
spray that instantly cools the plug, causing the metal to
contract and loosen. The spray is available at most auto
parts stores or online (search for “CRC Freeze-Off”).

Don't forget to set the gap of the new plugs before installing
them. Check the manual for gap specifications and use a
gap gauge (from any auto parts store).

Use just the right amount of force to tighten the plugs. If
you don't have a torque wrench, follow this general rule:
First, finger-tighten the plug. If the plug has a gasket, tighten
it an additional half turn using a plug wrench. If the plug
has a tapered seat, tighten it an additional one-sixteenth
turn.

Get Parts and More Online

You can find parts online for just
about any tractor ever made. Just
go to any search engine and type in
the brand followed by “parts.”

Lost the owner's manual? Search
for the manufacturer and “manual.”
If you're lucky, you'll find an online
version. If not, you'll have to order
one—and likely pay $30 or more.

Mytractorforum.com lets tractor
owners share questions and advice
on everything from selecting a new
tractor to servicing an older model.
Just scroll down to “lawn and garden
tractors” and select a category.

Replace the fuel filter

Fuel filter technique

Replace the fuel filter without making a mess. Pinch off the fuel line
with a clamp to stop any gas flow. As you remove the old filter, plug
the openings with your fingers.

An old fuel filter can cause hard starting, poor fuel economy,
maybe even an expensive carburetor rebuild. Check
your owner's manual to find out how often to replace the
filter.

Replacing the fuel filter is easy. But there's a trick to
doing it without getting drenched in gasoline. First,
pinch the fuel line leading from the tank with a clamp.
Then move the spring
clamps away from the filter
with pliers. Slip on a pair
of nitrile gloves, tilt the
inlet side of the filter up
and remove the inlet hose.
Drain the small amount of
fuel from the fuel line into
a drain pan. Then, plug the
filter inlet with your thumb,
tilt the entire filter down, and pull it out of the outlet
hose. This technique keeps most of the fuel inside the filter,
reducing spillage. Place the old fuel filter in the drain
pan and install the new filter. Pay attention to the fuel
flow direction arrows—the arrow must point toward the
engine. Move the fuel line clamps back into place and
remove the “pinch-off” clamp from the fuel line.

Tip: Get a smaller gas
can. Old gas (stored
for more than 30
days) is the most
common cause
of starting
problems.

Other Lawnmower Models

We show a John Deere tractor in this story, but the maintenance is similar for
other brands. Just be sure to follow the procedures, service intervals, and
lubricant and torque specifications shown in your owner's manual.

Zero-turn mowers
“ZTR” mowers have a
hydraulic steering system, requiring
you to change the hydraulic fluid and
filter occasionally (typically every 300
hours). It's a quick, simple job, a lot
like changing the motor oil.

Service schedules
Every manufacturer recommends
different “service
intervals” for things like oil,
filter and spark plug changes.
These intervals can vary a
lot. Many manufacturers recommend
greasing moving
parts every 50 hours, but
some call for it every 25
hours. So don't follow general
guidelines—follow your
manual.

Choose the right oil

Replace the oil filter

Screw on the new oil filter until the rubber gasket
touches the seat. Then give the filter another
half turn. Spread a light coat of oil on
the gasket so it doesn’t bind against the
seat.

Check the oil grade stamp

Check the “donut” on the back of
the container and be sure to buy oil
with an “SM” rating.

Just like your car, your tractor needs regular oil
changes. If your owner's manual suggests a brand
of oil, you can ignore that advice. But do pay attention
to the recommended viscosity (such as 10W-
30). If you use your tractor for snow removal,
check the manual for a “winter weight” oil recommendation.
Never, ever change the oil without also
changing the oil filter. To prevent a buildup of
gunk on the engine, wipe up any spilled oil. Bottle
the old oil and take it to your nearest oil recycling
center for disposal.

Blade-changing tips

Photo 1: Loosen stubborn bolts

Loosen stubborn
blade bolts with a
long breaker bar. Hold
back the blade with
wood blocks and a
C-clamp. A clamp on
the rear wheel stops the
deck from rolling as you
flip it over.

Photo 2: Install new blades

Position the new
blades in a “U” pattern
for better balance
and less vibration.
Tighten blade bolts with
a torque wrench to
avoid breaking them.

Dull blades make the engine and belts work harder.
They're bad for your grass, too. Instead of slicing off
the grass cleanly, they leave a torn edge that takes
longer to heal.

To change blades safely, remove the mower deck
instead of working from underneath the tractor.

If the deck has wheels, it tends to roll away as you
try to flip it over. Lock one wheel with a clamp as
shown in (Photo 1) above. Lay the deck on a couple of
2x4s to prevent damage to the pulleys.

Lock the blades in place with a clamp and blocks as
shown. Don't simply wedge a block between the
blade and deck; the blade can break free and cut
you.

If you're an Olympic weightlifter, you can loosen
the blade bolts with an ordinary wrench or ratchet.
If not, use a 25-in.
breaker bar and six-point
socket (about $25 for
both at home centers
and hardware stores).

Blade changes are less
hassle if you keep a
spare set handy. You
can sharpen the dull
ones in your spare
time or take them in
for professional sharpening.
For sharpening tips, type “mower blade” in the search box above.

Grass buildup on the underside of the deck
reduces cutting efficiency. Scrape off big chunks
with a flat pry bar and clean up the rest with a
putty knife.

To avoid over-tightening blade bolts, check the
specs in the owner's manual and use a torque
wrench (about $50 at home centers and hardware stores).
Truth is, many tractor owners get by without a
torque wrench. But if you ever break a bolt,
remember that we warned you.

Tip: Cutting tall grass is
very hard on belts.
If you've let the
grass go too long
between cuttings,
mow in half swaths
to reduce the load
and extend
belt life.

Clean the air filter between changes

Clean the filters

Wash the foam prefilter and blow off the
filter at least once a month during the
dusty mowing season.

You already know that it's important to
change the air filter as often as the owner's
manual recommends. But it's also a good
idea to clean the filter between changes. If
your tractor has a foam prefilter, wash it
with soap and water; never use a solvent
or other cleaner. Blow out the pleated
paper filter with a light blast from an air
compressor. Keep in mind that this is not
a substitute for regular filter changes. Even
if the filter looks clean, replace it with a
new one at recommended intervals.

3 Easy Winterization Steps

Before your tractor hibernates for
the winter, take a few minutes to
prevent springtime troubles.

Moisture inside an unused engine
leads to corrosion. “Fogging“ the
engine—spraying an oily mist
into each cylinder—prevents this.
All you have to do is remove the
spark plugs and blast in some
aerosol fogging spray (at auto
parts stores). Then reinstall the
spark plugs.

Storing a battery that isn't fully
charged can lead to permanent
damage, especially in cold weather.
Connect the battery to a battery
charger and charge it until
you get a reading of 12.7 volts.

Stored gas will slowly gum up the
whole fuel system, and the repairs
can be expensive. So add a fuel
stabilizer such as STA-BIL or
Seafoam (at auto parts stores)
to the gas tank before winter.
(Adding stabilizer to your gas can
year-round is also a good idea.)
But remember that stabilizers
aren't effective in gas that contains
ethanol. If you don't know
whether the gas contains ethanol,
run the engine until the tank is
empty.

Cover the air intake and exhaust
openings with plastic wrap or aluminum
foil to keep critters from
homesteading in your engine over
winter.

Grease guidance

Add new grease

Pump grease into the fitting until all the dark old grease is purged and fresh new
grease oozes out.

It isn't exactly rocket science, but many tractor owners goof up greasing. The biggest
mistake is using the wrong grease. The brand doesn't matter, but use the type recommended
by the manufacturer, whether it's plain lithium, lithium with molybdenum
disulfide, or poly urea. Grease every fitting every time you change the oil. Check your
owner's manual to locate them all. There may be grease fittings on your mower deck
and other attachments too. A flexible hose makes reaching the fittings a lot easier. Pick
up a grease gun and hose at any home center or auto parts store (about $25 for both).

Fix tubeless tire leaks

Photo 1: Break both beads

Cut a 45-degree angle on a short piece of 2x2. Place
the angled edge right where the tire meets the steel wheel.
Then smack it with a maul to break the tire bead away from
the wheel. Move the 2x2 around the entire edge until the
bead is completely detached. Flip over the wheel and break
the bead on the opposite side.

Photo 2: Pry off the tire

Pry the tire bead up with a large screwdriver. Hold that
part of the tire away from the wheel and use a second
screwdriver to pry up another section. Repeat until the entire
bead is off.

Photo 3: Pry the tire back onto the wheel

Once the inner tube is in place, hold the valve stem with
a spring clamp. Then slide the round handle ends of two
large adjustable wrenches (a screwdriver will puncture the
tube) under the bead and pry it up and then back onto the
wheel.

Got a garden tractor tire that’s always low and you can’t find a
puncture? Chances are you’ve got a bead leak caused by a rusting
wheel. You can yank the tire, remove the corrosion from the wheel
with a wire wheel and then paint it, but my guess is that the tire
will still leak air. That’s way too much trouble to wind up back
where you started. Just install an inner tube and put an end to
deflated tires. Write down the tire size and buy the same size tube.

Start by cutting off the old valve stem with a side
cutters or utility knife. Next, break the bead (Photo 1). Slide a large
screwdriver or pry bar down the center of the wheel and clamp it in
a vise. Then pry the bead off the wheel (Photo 2).

Rotate the inner tube so the valve stem lines up with the valve
stem hole in the wheel. Tuck the inner tube inside the tire and pull
the valve stem through the hole. Secure the valve stem with a
spring clamp. Then pry the tire bead back onto the wheel and
reinflate (Photo 3).